Atmospheric Overturning Circulation on Dry, Tidally Locked Rocky Planets Is Mainly Driven by Radiative Cooling

In this study, we examine the driving mechanism for atmospheric overturning circulation on dry, tidally-locked rocky planets without condensation of water vapor or other species. We find that main process is radiative cooling CO2 (or non-condensable greenhouse gases) rather than warming stellar radiation. Stellar radiation ultimate but not direct mechanism. Due to combination uneven distribution in and effective horizontal energy transports free troposphere, there strong temperature inversion area away from substellar region. This makes have a effect atmosphere, same as stratosphere Earth's atmosphere. produces negative buoyancy drives large-scale downwelling, supporting formation global-scale circulation. If excluded becomes very weak, regardless level completely different Earth moist, planets, where latent heat release and/or baroclinic instability are dominated mechanisms. Our study improves understanding exoplanets also dry such Venus Mars solar system.